Animation 1) Circular Loading Animation. You see this type of animation when a webpage is loading. The trick in this animation is to create the circular process diagram that spins.Animation 2) Linear Loading Animation. This type of animation is common in file download options.
The bar is created using multiple rectangles and the trick is in animating them in sequence to create a natural loading effect.

So depending on what type of effect you want to create, you can use one of these 2 effects in you presentations.

Hope you find the animations simple and easy to use in your presentation!